/* ===== CSS Variables & Theme ===== */
:root {
    /* Colors - Simplified palette */
    --bg-primary: #0f0f1a;
    --bg-secondary: #161625;
    --bg-tertiary: #1e1e30;
    --bg-card: #252540;
    --bg-hover: #2a2a45;
    
    --text-primary: #ffffff;
    --text-secondary: #b8b8d0;
    --text-muted: #7878a0;
    
    --accent-primary: #667eea;
    --accent-secondary: #764ba2;
    --accent-cyan: #00d4ff;
    --accent-pink: #ff6b9d;
    --accent-green: #00e676;
    --accent-orange: #ffab40;
    
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-glow: linear-gradient(135deg, rgba(102, 126, 234, 0.4) 0%, rgba(118, 75, 162, 0.4) 100%);
    
    --border-color: rgba(255, 255, 255, 0.08);
    --border-light: rgba(255, 255, 255, 0.12);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 30px rgba(102, 126, 234, 0.25);
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

/* ===== Reset & Base Styles ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ===== App Container ===== */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: 
        radial-gradient(ellipse at 30% 0%, rgba(102, 126, 234, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 100%, rgba(118, 75, 162, 0.12) 0%, transparent 50%),
        var(--bg-primary);
}

/* ===== Header ===== */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) var(--spacing-xl);
    background: rgba(22, 22, 37, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo-icon {
    width: 42px;
    height: 42px;
    animation: logoFloat 6s ease-in-out infinite;
}

@keyframes logoFloat {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-3px) rotate(5deg); }
}

.logo-text h1 {
    font-size: 1.3rem;
    font-weight: 600;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.logo-text span {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 400;
}

.nav-tabs {
    display: flex;
    gap: 4px;
    background: var(--bg-tertiary);
    padding: 4px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.nav-tab {
    padding: 10px 24px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-family: var(--font-primary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.nav-tab:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-tab.active {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-glow);
}

/* ===== Main Content ===== */
.main-content {
    display: grid;
    grid-template-columns: 300px 1fr 360px;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    flex: 1;
    min-height: 0;
}

@media (max-width: 1400px) {
    .main-content {
        grid-template-columns: 250px 1fr 280px;
    }
}

/* ===== Panels ===== */
.panel {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(180deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    border-bottom: 1px solid var(--border-color);
}

.panel-header h2 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

.reset-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
    font-family: var(--font-primary);
    font-size: 0.8rem;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.reset-btn:hover {
    background: rgba(255, 107, 157, 0.15);
    color: var(--accent-pink);
    border-color: var(--accent-pink);
}

/* ===== Controls Panel ===== */
.controls-panel {
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-light) transparent;
}

.controls-panel::-webkit-scrollbar {
    width: 5px;
}

.controls-panel::-webkit-scrollbar-track {
    background: transparent;
}

.controls-panel::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 3px;
}

.controls-section {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.controls-section:last-child {
    border-bottom: none;
}

.controls-section h3 {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
}

/* Polarization Selector */
.polarization-selector {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.pol-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-family: var(--font-primary);
    font-size: 0.7rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.pol-btn:hover {
    background: var(--bg-hover);
    border-color: var(--border-light);
    color: var(--text-primary);
    transform: translateY(-1px);
}

.pol-btn.active {
    background: var(--gradient-glow);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.2);
}

.pol-icon {
    font-size: 1.3rem;
}

/* Slider Groups */
.slider-group {
    margin-bottom: var(--spacing-lg);
}

.slider-group:last-child {
    margin-bottom: 0;
}

.slider-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.slider-header label {
    font-size: 0.85rem;
    color: var(--text-primary);
    font-weight: 500;
}

.slider-value {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent-cyan);
    background: rgba(0, 212, 255, 0.1);
    padding: 3px 10px;
    border-radius: 20px;
}

/* Custom Range Slider */
input[type="range"] {
    width: 100%;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--bg-tertiary);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--gradient-primary);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.4);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.5);
}

input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--gradient-primary);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.4);
}

.slider-range {
    display: flex;
    justify-content: space-between;
    margin-top: 6px;
    font-size: 0.65rem;
    color: var(--text-muted);
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.checkbox-label:hover {
    color: var(--text-primary);
}

.checkbox-label input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 18px;
    height: 18px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: var(--gradient-primary);
    border-color: var(--accent-primary);
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    color: white;
    font-size: 0.65rem;
    font-weight: bold;
}

/* Playback Controls */
.playback-controls {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.playback-btn {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.playback-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.playback-btn:first-child {
    width: 56px;
    background: var(--gradient-primary);
    border-color: var(--accent-primary);
    color: white;
}

.playback-btn:first-child:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-glow);
}

.hidden {
    display: none !important;
}

/* ===== Visualization Section ===== */
.visualization-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.canvas-container {
    flex: 1;
    position: relative;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    min-height: 480px;
    box-shadow: inset 0 0 60px rgba(0, 0, 0, 0.3);
}

#mainCanvas {
    width: 100%;
    height: 100%;
    display: block;
}

.canvas-overlay {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    right: var(--spacing-md);
    display: flex;
    justify-content: center;
    pointer-events: none;
}

.view-controls {
    display: flex;
    gap: 4px;
    background: rgba(15, 15, 26, 0.9);
    backdrop-filter: blur(10px);
    padding: 4px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    pointer-events: auto;
}

.view-btn {
    padding: 8px 16px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-family: var(--font-primary);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.view-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.view-btn.active {
    background: var(--accent-primary);
    color: white;
}

.visualization-info {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.info-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.info-label {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.info-value {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent-cyan);
}

.color-indicator {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
}

.color-swatch {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    background: #ff6b00;
    border: 2px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 0 15px currentColor;
}

/* ===== Info Panel ===== */
.info-panel {
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-light) transparent;
}

.info-panel::-webkit-scrollbar {
    width: 5px;
}

.info-panel::-webkit-scrollbar-track {
    background: transparent;
}

.info-panel::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 3px;
}

.tab-content {
    display: none;
    flex-direction: column;
    flex: 1;
}

.tab-content.active {
    display: flex;
}

.info-section {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.info-section:last-child {
    border-bottom: none;
}

.info-section h3 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: 10px;
}

.info-section h3::before {
    content: '';
    width: 3px;
    height: 16px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

/* Formula Cards */
.formula-card {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
    margin-bottom: 10px;
    border-left: 3px solid var(--accent-primary);
}

.formula-card:last-child {
    margin-bottom: 0;
}

.formula {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.formula-label {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent-pink);
}

.formula-expr {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-primary);
}

.formula-result {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.formula-result span:last-child {
    font-family: var(--font-mono);
    color: var(--accent-green);
}

/* Quantity Grid */
.quantity-grid {
    display: grid;
    gap: 10px;
}

.quantity-item {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
    display: grid;
    gap: 4px;
}

.quantity-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.quantity-value {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent-cyan);
}

.quantity-formula {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Polarization Info */
.polarization-info {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.jones-vector, .stokes-params {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
}

.jones-label, .stokes-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    display: block;
}

.jones-matrix {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--accent-primary);
}

.matrix-bracket {
    font-size: 2rem;
    font-weight: 200;
    color: var(--text-muted);
}

.matrix-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.stokes-values {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-secondary);
}

/* Theory Content */
.theory-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.theory-card {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
    margin-bottom: 10px;
    border-left: 3px solid var(--accent-primary);
}

.theory-card:last-child {
    margin-bottom: 0;
}

.theory-card h4 {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.theory-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Math Block */
.math-block {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
    margin-top: 10px;
}

.math-block p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.equation {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-cyan);
    padding: 10px;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    margin-bottom: 6px;
    text-align: center;
}

.param-list {
    list-style: none;
    padding-left: var(--spacing-md);
}

.param-list li {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    position: relative;
}

.param-list li::before {
    content: '→';
    color: var(--accent-primary);
    position: absolute;
    left: -16px;
}

.param-list li strong {
    font-family: var(--font-mono);
    color: var(--accent-pink);
}

/* Constants Grid */
.constants-grid {
    display: grid;
    gap: 8px;
}

.constant-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.constant-name {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.constant-value {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent-cyan);
}

/* Advanced Content */
.jones-examples {
    display: grid;
    gap: 8px;
    margin-top: 10px;
}

.jones-example {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 12px;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
}

.jones-example span:first-child {
    color: var(--text-secondary);
}

.jones-vec {
    font-family: var(--font-mono);
    color: var(--accent-primary);
}

.feature-list {
    list-style: none;
    padding: 0;
    margin-top: 10px;
}

.feature-list li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature-list li:last-child {
    border-bottom: none;
}

.feature-list li::before {
    content: '•';
    color: var(--accent-primary);
    font-size: 1.2rem;
}

/* Applications Grid */
.applications-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.app-card {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 14px;
    transition: all var(--transition-normal);
    border: 1px solid transparent;
}

.app-card:hover {
    background: var(--bg-hover);
    transform: translateY(-2px);
    border-color: var(--border-light);
}

.app-card h4 {
    font-size: 0.85rem;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.app-card p {
    font-size: 0.75rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* ===== Footer ===== */
.footer {
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.separator {
    color: var(--accent-primary);
}

/* ===== Responsive Design ===== */
@media (max-width: 1400px) {
    .main-content {
        grid-template-columns: 280px 1fr 320px;
    }
}

@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 220px 1fr 240px;
    }
    
    .visualization-info {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr auto;
    }
    
    .controls-panel {
        order: 2;
    }
    
    .visualization-section {
        order: 1;
    }
    
    .info-panel {
        order: 3;
    }
    
    .canvas-container {
        min-height: 380px;
    }
}

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: var(--spacing-md);
        padding: var(--spacing-md);
    }
    
    .nav-tabs {
        width: 100%;
        justify-content: center;
    }
    
    .main-content {
        padding: var(--spacing-md);
    }
    
    .visualization-info {
        grid-template-columns: 1fr 1fr;
    }
    
    .applications-grid {
        grid-template-columns: 1fr;
    }
    
    .polarization-selector {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .logo-text h1 {
        font-size: 1.1rem;
    }
    
    .nav-tab {
        padding: 8px 16px;
        font-size: 0.8rem;
    }
    
    .visualization-info {
        grid-template-columns: 1fr;
    }
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.info-section {
    animation: fadeIn 0.4s ease forwards;
}

/* ===== Custom Scrollbar for Webkit ===== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}